Powered ride-on concrete finishing machines are well known in the art and typically include a pair of engine-driven rotors each of which carries a plurality of troweling or finishing blades that support the machine and ride over the surface of a poured concrete floor or deck. The rotors and attached blades include a system for applying downward pressure to the blades to tilt the rotors relative to the frame to provide directional control of the finishing machine, all in a manner well known in the art. Ride-on trowels of the foregoing type also utilize a system to vary the pitch of the blades depending on operating conditions. These arrangements are also well developed in the prior art.
Such prior art machines typically have a supporting frame that carries the drive engine, the rotor and the blade assemblies, and an operator's seat and control arrangement, again, all in a manner well known in the art. In one prior art device, the drive engine is mounted directly above one of the rotors via a gear box and is connected to the other rotor with a drive shaft. This offset mounting of the engine results in a machine imbalance and, therefore, is limited to use in smaller trowels that use lightweight engines. As trowel size is increased, higher power heavier engines are needed which cause a machine imbalance. In another prior art arrangement, the drive engine is mounted centrally on the frame between the two rotor assemblies and driving power is transmitted directly from the engine to a drive shaft arrangement below the engine via a clutch and belt arrangement. A particular problem with this type of drive arrangement is that the belt and clutch arrangement is difficult to access because of its central location beneath the engine. Also, in order to replace the drive belt, one of the main drive shafts, carrying the driven pulley and drive belt arrangement, must be disassembled.